贵州织金上二叠统泥岩地球化学特征及层序界面响应

基于对贵州织金J2井区上二叠统岩芯观测及泥岩(ICP-MS)微量及稀土元素分析测试结果，探讨了泥岩地球化学特征及其层序界面响应。结果表明：泥岩微量元素V,Co,Ni,Cu相对富集，Cr及Rb相对亏损，其余微量元素含量接近上地壳含量；稀土元素总量较高，w (LREE)/w (HREE)及 w (La)N/ w (Yb)N等比值显示轻、重稀土分异明显；V/(V+Ni),Sr/Ba,Ce/Ce*,Ceanom指示了泥岩均处于海陆交互相背景的缺氧环境条件下。∑REE与亲石元素Nb,Ta,V,Ga,Rb,Th,Ba,Sr呈显著或临界正相关，与元素Co,Ni,Mo,Zn和Cu相关性不明显或呈微弱负相关，指示了稀土元素主要来源于陆源碎屑矿物；稀土元素分布模式和 w (∑REE)- w (La)/ w (Yb)图显示物源主要来自峨眉山玄武岩，并存在部分沉积岩及花岗岩混入；泥岩层中∑REE, w (LREE)/ w (HREE),(La/Yb)N,Eu/Eu*,Ceanom,V/(V+Ni),Sr/Ba等微量及稀土元素参数的异常波动面与层序界面(SB2,SB3,SB4)存在一定程度的对应关系，记录了沉积过程古水体的地球化学条件，可为无海相标志层沉积区钻井地层精细对比提供地球化学证据。

Characteristic and recognition of sequence boundary of trace and rare earth elements in Late Permian mudstone in well J2 area,Zhijin,Guizhou Province

Based on ICP-MS analysis,the measurement of the REEs and trace elements were carried out on Late Permain mudstone in well J2 area,Zhijin,Guizhou,for the research of its geochemical characteristics and the recognition of sequence boundary.Geochemical analyses reveal that trace elements V,Co,Ni,Cu are slightly enriched,elements Cr and Rb are depleted,and the contents of the remaining elements are close to the averages of that for the upper crust.The total content of REEs is high.The ratios of w (LREE)/ w (HREE) and w (La)N/ w (Yb)N indicate an apparent differentiation of LREEs and HREEs.The ratios of V/(V+Ni),Sr/Ba,Ce/Ce* and Ceanom suggest that mudstone developed in the anoxic conditions of marine-terrigenous facies.∑REE has a significantly or critically positive correlation with lithophile elements Nb,Ta,V,Ga,Rb,Th,Ba,Sr and a negative or no obvious correlation with elements Co,Ni,Mo,Zn,Cu,indicating that REEs originate mainly from terrigenous minerals.The distribution patterns of REEs and w (∑REE)- w (La)/ w (Yb) diagram demonstrate that the source rocks of these samples are dominantly Emeishan basalt,as well as a small part of sedimentary rocks and granite.Abnormal surfaces near the sequence boundaries(SB2,SB3,SB4) correspond significantly with the boundaries,identified by relative geochemical indicators of REEs and trace elements,such as ∑REE, w (LREE)/ w (HREE),(La/Yb)N,Eu/Eu*,Ceanom,(V/V+Ni),and Sr/Ba.In addition,geochemical indicators record the geochemical conditions of water-body in sedimentary process,which can provide a geochemical evidence for the fine stratigraphic correlation in the sedimentary area where marine maker beds were not developed.